
%0 Journal Article
%A Curtis, NJ 
%T N-Alkylations and O-Alkylations of Nitro-Substituted 1,3-Diphenylureas: Preparations of Propellant Stabilizer Derivatives
%J Australian Journal of Chemistry
%D 1988/04/01
%V 41
%N 4
%P 585-595
%K 
%R https://doi.org/10.1071/CH9880585
%U https://www.publish.csiro.au/paper/CH9880585 
%X A procedure has been developed for the N- ethylation and methylation of 1,3-diphenylureas, ArNRCONHAr&#8242; (R = H, Me or Et), through treatment with sodium hydride and iodoalkane in dimethylformamide. The reaction was general, provided that the aniline to be alkylated was substituted with no more than one nitro group. ArRNCONR&#8242;Ar&#8242; derivatives prepared were: R = R&#8242; = Et (and Me); Ar = phenyl, Ar&#8242; = 2-nitrophenyl and 4- nitrophenyl ; Ar = 2-nitrophenyl, Ar&#8242; = 2-nitrophenyl and 4-nitrophenyl; Ar = Ar&#8242; = 4-nitrophenyl. Two mixed derivatives were also prepared: R = Et, R&#8242; = Me, Ar = phenyl, Ar&#8242; = 2-nitrophenyl and 4-nitrophenyl. O-Alkylated isourea products were obtained in the reactions of 1-(2,4- dinitrophenyl )-3-(2-nitrophenyl)urea and 1-(2,4-dinitrophenyl)-3-(4- nitrophenyl )urea. The use of potassium carbonate as the base led to apparently exclusive O- alkylation of 1,3-bis(2-nitrophenyl)urea although the reaction was not general. 1-(2,4-Dinitrophenyl)-1,3- diethyl-3-phenylurea was prepared by using silver oxide and obtained as a mixture with the isourea . Many of the compounds prepared are important nitro derivatives of the propellant stabilizers, ethyl and methyl centralite. 
